Night vision devices are widely used in the military to provide soldiers, aviators and sailors with the ability to view objects at night or during other low light conditions. As a result, many night vision devices are currently being manufactured according to exacting military specifications and designs. Similarly, many such night vision devices are being manufactured for specific military applications such as part of the sights of various weapons or as part of goggle assemblies that attach to an aviator's or soldier's helmet. As a consequence, many of the night vision devices currently being manufactured are neither affordable nor easily adapted to non-military uses by the general public.
As the military demands for night vision devices wane, manufacturers of night vision devices are starting to produce commercial products for sale to the general public. Night vision devices typically use sophisticated optics and electronics that make such devices very expensive. As a result, many commercially sold night vision devices are built into specialty optical devices that appeal to specific markets willing to pay the high cost. For example, night vision camera attachments are manufactured to attach 35 mm cameras. These devices are sold to photographers and journalists who want to take pictures at night. Night vision rifle scopes are sold to hunters who want to shoot nocturnal varmints or hunt during low light conditions. Night vision binoculars are sold to commercial fishermen and other boaters who want to navigate through various boating channels at night. A disadvantage of such specialty night vision devices is that they are typically designed for one specific application and can not be used in multiple applications. For instance, night vision boating binoculars can not be coupled to a camera to take pictures at night. Similarly, a night vision camera attachment can not typically be joined to a hunting scope because of incompatible optical designs.
A need therefore exists for a single low cost night vision device that can be used in multiple applications and can be used in conjunction with most every type of optical device. As a result, with a one time purchase of a night vision device, a person can join that device to a camera, video recorder, rifle scope, telescope or any other optical device, thereby converting that optical device into a night vision device.
ITT Corporation, the assignee herein, manufactures many night vision devices for various applications. An example of a night vision rifle scope is shown in U.S. Pat. No. 5,084,780 to Phillips entitled TELESCOPE SIGHT FOR DAY/NIGHT VIEWING. An example of a night vision camera attachment is the commercially sold Model F6010 Pocketscope. A binocular viewing device is exemplified by co-pending U.S. patent application Ser. No. 08/108,989 entitled NIGHT VISION BINOCULARS, now U.S. Pat. No. 5,495,364. Lastly, a monocular viewing device is exemplified by co-pending U.S. patent Ser. No. 08/152,193 entitled, MONOCULAR NIGHT VISION DEVICE, now abandoned.
Night vision devices typically utilize an image intensifier tube that amplify low level light to create a visible image. An objective lens assembly directs the low intensity light into the image intensifier tube. The visible image created by the image intensifier tube is viewed through an eyepiece assembly. In many night vision devices the image is collimated and/or inverted between the image intensifier tube and the eyepiece assembly. The optics comprising the objective lens assembly, eyepiece assembly, inverter and collimator add significantly to the cost of night vision devices. Furthermore, such optical elements consume a large amount of space, making the night vision device large and bulky. Such optical elements also are heavy making the overall night vision device too massive to join to other delicate optical devices.
It is therefore an object of the present invention to provide a small lightweight night vision device using a minimal amount of optical elements and consuming the minimal amount of space.
It is a further object of the present invention to present a low cost night vision device that can be adapted to most every type of optical device, either as an objective lens attachment or as an ocular lens attachment.